Apparatus for insuring safety of traffic on single lines of railway.



' No. 832,709. PATENTED OUT. 9, 1906,

B. TYER & J. H. HAMILTON. APPARATUS FOR INSURING SAFETY OF TRAFFICON SINGLE LINES 0F RAILWAY. APPLICATION rum JAN.6

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No. 832,709.. PATENTED OCT. 9, 1906. E. TYER & J. H. HAMILTON. APPARATUS FOR INSIIRING SAFETY OF TRAFFIC 0N SINGLE LINES OF RAILWAY.

APPLIUATION FILED 1mm, 1904.

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WITH E8!!! 'No. 832709. PATENTED OCT. 9 190 NI SURING SAFETY OF TRAFFIC ON SINGLE LINES E. TYER & J. H. HAMILTO APPARATUS FOR IN or RAILWAY. .APPLIGAT'ION FILED JAN.6, 1904.

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mun-rungs? Q/IWIINIQII I UNITED STATES PATENT OFFICE.

EDWARD TYER, OF

DALSTON, ENGLAND, AND JAMES HENRY HAMILTON,

OF CAPE TOWN, OAPE COLONY.

APPARATUS FOR INSURING SAFETY OF TRAFFIC 0N SINGLE LINES 0F RAILWAY.

Specification of Letters Patent.

Patented Oct. 9, 1905,

ing at 145 Kloof street, Cape Town, Cape Colony, subjects of the King of Great Britain and Ireland, have invented certain new and useful Improvements in Apparatus for Insuring Safety of Traffic on Single Lines of Railway, of which the following is a specification, (for which we have applied for a patent in Great Britain, filed November 19, 1903, No. 25,263.)

It has been usual to provide in connection with various electrical systems for controlling and securing the safety of the traflic on single lines of railway a visual signal, preferably automatic in its working, to indicate to the operator the exact state of his apparatus and the condition of the section which itcontrols. In the usual form of apparatus heretofore employed in such connection the indicators hitherto employed for this purpose have been manually operated, and therefore liable, owing, for example, to lapse of memory on the part of the operator, to misrepresent the state of the apparatus and of the section of the line controlled by it.

The reason for the adoption of manuallyoperated indicators in the apparatus referred to is that tablets or staffs can be withdrawn from them on the receipt of'either positive or negative currents from the distant station, provided that the apparatus at the sending and receiving stations are in unison with each other-that is, provided that they are similarly connected with respect to the polarity of their respective batteries. That being so, it has not been possible to indicate the state of the apparatus or of the line by means of an indicator which responds only to a positive or to a negative current.

The present invention relates to an indicating apparatus which can be used in connection with such apparatus, and for this purpose the indicator 1s controlled by a pair of steel magnets each surrounded by a separate magnetizing-coil. One of these coils is arranged to be lnfiuenced by outgoing currents only, while the other is subject to incoming currents only. The indicator is attached to a pivotally mounted portion of the magnetic system, which is constrained to oocupy one of two positions, according to the magnetic condition of the system. Thus whenever a current passes through one of the coils of a kind to reverse the magnetism of the core the indicator will be moved from one position to the other. TVhen, therefore, the apparatus at two stations are in unison and the indicators show Tablet in and on receipt of a current from the distant station a tablet is withdrawn from the apparatus at the home station, the reversal of the polarity of the home battery with respect to the apparatus and the line consequent on the withdrawal of the tablet puts the two apparatus out of unison, so that when a current is sent from the home station the magnetism of the magnet afiected by outgoing currents is reversed, as is also the magnetism of the magnet at the distant station, which is subject to incoming currents. The indicators at both stations will therefore change their positions and show Tablet out, and subsequent currents will not affect the indicators until the polarity of one or other of the batteries has been reversed by the. insertion of the tablet. In the accompanying drawings, Figure 1 is a diagram showing an arrangement of the indicator apparatus, together with the line and battery connections for two stations controlling a given section of railway. Fig. 2 is a corresponding diagram showing a slightlymodi'fied arrangement of indicator apparatus, and Fig. 3 is a front elevation of the indicator apparatus of Fig. 1 with part of the cover removed. Fig. 4 is a back elevation, and Fig. 5 a sectional plan, of the same.

Referring to Figs. 1, 3 and 5, the indicator A at each station consists of a pair of permanent magnets a 1), shown horseshoe in form and having their limbs encircled by coils a b, respectively. The magnetizing force of these coils is arranged to be sufiicient, with the ordinary working current of the line, to reverse the magnetism of the cores when the current in the coils is reversed. The coils a,

are connected in the receiving-circuit and the coils b in the sending-circuit, as shown in Fig. 1. The pole-pieces a a b 11 extend inward from the cores and are arranged symmetrically with respect to the armature c, which consists of a hollow cylinder of soft iron closed at one end and slotted longitudinally through the greater part of its length from the open end, thus practically forming two equal segments of a hollow cylinder 0011- l the other nected by a plate at one end. Fixed to the armature c is an indicating-disk d, and the two are pivotally mounted on a pin supported in the casing e and a bracket e, attached thereto. The soft-iron armature being magnetized by induction by the magnets a b will take up one or other of two positions, depending on the polarity of the pole-pieces a a 6 6 The armature will always turn so as to present each of its segments to a pair of similar poles, and consequently if we assume the polarity of either of the magnets of Fig. 3

to be reversed the armature will turn through an angle of approximately ninety degrees. The direction of motion of the armature will be determined by the gravitational effect of the disk (1," but stops f may be provided to limit its movement. In one position of the armature one half of the indicating-disk is presented to a window g in the cover of the apparatus, and in the other position the other half of the disk is presented. Suitable indications, such as Tablet in or Line clear and Tablet out or Line blocked, are shown on the respective halves of the disk (1. One end of coils a in each instrument is connected to the receiving-stop of the telegraphic key B and the other end to earth, and one end of coil 1) in each instrument is connected, through the commutator C and battery D, to the sending-stop of the key B, the other end of the coil being connected to earth. The commutator O is operated in the wellknown manner in such apparatus by the insertion or withdrawal of a tablet, either of which operations reverses the commutator.

' In Fig. 1 the apparatus at the two stations X Y are in unisonthat is to say, similar poles of the station-batteries are connected to line. If now a tablet or staff is withdrawn from the apparatus at station Y, the commutator O at that station will be reversed, as shown in dotted lines, so that a current sent from that station to station X will be of different polarity to the previous current. The polarity of the pole-pieces b b at station Y will therefore be reversed, as will also the polarity of the pole-pieces a a at station X, and the indicating-disks at both stations will change their positions. Subsequent currents in either direction between the two stations will result in no further movement of the indicators so long as the positions of the commutators remain unchanged; 1 but if one of the commutatorssay that at station X is reversed by the insertion of the tablet the apparatus are again brought into unison, and the first current sent from station X reverses the polarity of the pole-pieces b b at that station and at the same time the polarity of the pole-pieces a a at station Y. The indicating-disks are therefore returned to their original positions, and the apparatus at the two stations are in unison, but with poles of their batteries now connected to line.

In the modified construction shown diagrammatically in Fig. 2 the only difference is that instead of using a soft-iron armature adapted to turn on a pivot between the polepieces of a pair of horseshoe-magnets the soft-iron armature is dispensed with and only oneof the magnets m is horseshoe-shaped, the other magnet 17. being a simple bar. This latter magnet is pivotally mounted on its long axis and has fixed to it at one end a steel finger or projection M, which forms a polepiece and extends toward the pole-pieces m m of the horseshoe-magnet. The two magnets are provided with coils, m n, respectively, similarly connected with respect to the circuits as the coils a b in the arrangement of Fig.1. The indicating-disk is carried on the finger n or it itself may serve as the indicator.

Having thus described the nature of our said invention and the best means we know of carrying the same into practical effect, we claim- 1. In an indicator, a pair of electromagnets, each having a separate magnetizingcoil and a single magnetic indicator common to both coils and arranged to. change its position on reversal of magnetism of either of the magnets; substantially as described.

2. An indicator comprising a pair of steel .magnets each having a magnetizing-coil, and

a movable magnetic part, the coils being so connected with respect to the signaling-battery of a station that the first current sent ICC after the withdrawal or insertion of a staff ortablet at the station will cause the movable part to change its position, substantially as described. I

3. An indicator comprising a pair of steel magnets each having a magnetizing-coil, and a movable magnetic part, the coils being so connected with respect to the line between two signaling-stations that the first current received after the withdrawal or insertion of a staff or tablet at the distant station will cause the movable part to change its position, substantially as described.

4. Apparatus'for automatically indicating the condition of a given section of a staff or tablet worked single line comprising at each station controlling the section a pair of steel magnets each provided with a separate magnetizing-coil, one of the said coils being traversed by incoming currents only and Y the other coil by outgoing currents only, and a movable magnetic part which is constrained to occupy one of two definite positions, substantially as described.

5. Apparatus for automatically indicating the condition of a given section of a stafi or tablet worked single line comprising at each station controlling the section a pair of steel magnets each having a magnetizing-coil, and a movable magnetic part, the coils being so connected with respect to the line and station batteries that the first current sent after the withdrawal or insertion of a staff or tablet at either station will reverse the magnetism of one of the magnets at each station and cause the movable parts to change their position,csubstantially as described.

6. In electrical apparatus for working the traffic on single lines of railway in which the issue of a staff or tablet may be controlled by currents of either polarity, a pair of electromagnetic indicators, one at each station controlling a section, said indicators being adapt ed to be affected by the first current which traverses the line between the two stations after the withdrawal or insertion of a staff or tablet at either station, substantially as described.

7. In electrical apparatus for working the traffic on single lines of railway in which the.

issue of a staff or tablet may be controlled by currents of either polarity, a pair of electromagnetic indicators, one at each station controlling a section, each consisting of two steel magnets provided with magnetizing-coils and a movable magnetic part adapted to change its position each time the magnetism of either of the steel magnets is reversed, substantially as described.

8. In electrical apparatus for working the traffic on single lines of railway in which the issue of a staff or tablet may be controlled by currents of either polarity, a pair of electromagnetic indicators, one at each station controlling a section, each consisting of two steel magnets provided with magnetizing-coils and a movable magnetic part, the coils being so connected with respect to the line and battery circuits that the first current which traverses the line after a tablet or staff has been withdrawn or inserted at either station reverses the magnetism of one of the magnets of each indicator while subsequent currents do not affect their magnetic condition until such tablet or staff has been again inserted or withdrawn at either station, substantially as described.

9. In apparatus of the kind herein described an electromagnetic indicator comprising a pair of horseshoe steel magnets each provided with a magnetizing-coil a softiron armature consisting of a split hollow cylinder pivotally mounted between the polepieces of the magnets and an indicating-disk attached to the movable armature, substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

EDWARD TYER. JAMES HENRY HAMILTON. Witnesses:

GEORGE HENRY IELFs, W. M. HARRIS. 

